Choice of passive or active: letters
Example 1

Dear Sir or Madam, 
I am writing in connection with a PH PhotoFinish 2000 printer that I purchased / was purchased from your branch at 100 Queen's Road Central on 28 November 2005. 
At the time of purchase I was told / your sales assistant told me that I would be able to buy replacement ink cartridges 'long beyond the life of the printer' and that you would always have them in stock.
You might imagine my surprise and disappointment / My surprise and disappointment might be imagined, therefore, when last week I was told by staff at your Mong Kok branch / staff at your Mong Kok branch told me that the printer had been discontinued / the manufacturer had discontinued the printer and it was no longer possible to obtain replacement ink cartridges. I am sure you will appreciate / it will be appreciated that I would never have spent HK$ 2,200 / HK$ 2,200 would never have been spent on a printer that could be used / customers could use for little over a year.
To resolve the problem, I would appreciate it / it would be appreciated if you could look into the matter / the matter could be looked into, and if it proves to be the case that replacement cartridges are on longer available, agree to replace my printer with a model of similar specifications for which cartridges are obtainable.
Yours sincerely, 

Example 2

We write to advise you that / You are advised that at the close of business on 15/04/06, our records show that withdrawals from your above-mentioned account exceeded the available balance by HKD 1,346,758 on which debit interest is payable.
To minimize your interest charges, may we ask that you/ you are asked to arrange to transfer or deposit sufficient funds to put your account in order as soon as possible.
You may, of course, have already done so / This may, of course, have already been done, in which case please disregard this letter / this letter should be disregarded and accept our thanks for your co-operation.
For any further assistance, please do not hesitate to contact us on 2340 9797

Answer
Note that in most of these examples, the choice of passive or active is a matter of tone, not grammatical correctness.
For example, in the letter 2, line(4) 'you are asked to arrange...', is perfectly correct grammatically. However, 'may we ask that you arrange...', is rather more polite in tone. 
Example 1
Dear Sir or Madam, 
I am writing in connection with a PH PhotoFinish 2000 printer that I purchased / was purchased from your branch at 100 Queen's Road Central on 28 November 2005. 
At the time of purchase I was told / your sales assistant told me that I would be able to buy replacement ink cartridges 'long beyond the life of the printer' and that you would always have them in stock.
You might imagine my surprise and disappointment / My surprise and disappointment might be imagined, therefore, when last week I was told by staff at your Mong Kok branch / staff at your Mong Kok branch told me that the printer had been discontinued / the manufacturer had discontinued the printer and it was no longer possible to obtain replacement ink cartridges. I am sure you will appreciate / it will be appreciated that I would never have spent HK$ 2,200 / HK$ 2,200 would never have been spent on a printer that could be used / customers could use for little over a year.
To resolve the problem, I would appreciate it / it would be appreciated if you could look into the matter / the matter could be looked into, and if it proves to be the case that replacement cartridges are on longer available, agree to replace my printer with a model of similar specifications for which cartridges are obtainable.
Yours sincerely, 

Example 1

We write to advise you that / You are advised that at the close of business on 15/04/06, our records show that withdrawals from your above-mentioned account exceeded the available balance by HKD 1,346,758 on which debit interest is payable.
To minimize your interest charges, may we ask that you/ you are asked to arrange to transfer or deposit sufficient funds to put your account in order as soon as possible.
You may, of course, have already done so / This may, of course, have already been done, in which case please disregard this letter / this letter should be disregarded and accept our thanks for your co-operation.
For any further assistance, please do not hesitate to contact us on 2340 9797