Problem with Santander... Any advice?

Lb86

Hi, This may be a long post so I will apologise in advance but I am having real problems with Santander and wondered if anyone can advise me. In 2000 I opened an account with alliance and leicester and never had any problems until 2008 when the account went £1.57 overdrawn, as I was no longer using the account I was unaware that fees were being added at £5 a day until I got a statement showing I was now £200 overdrawn. I closed the account and agreed with them that as I was putting a complaint in (at their reccomendation due to the bank charge court case) that I did not need a formal payment plan however I paid £20 a week into the account until I got it down to £40. I completely forgot I had the account until Santander contacted me 2 months ago saying that I owed them £140 and it would continue to rise at £100 a month due to overdraft fees. I called them to be told that I had to pay it and they wouldn't close the account as I wasn't meeting the payment plan I had in place with A&L I asked the lady for details of the payment plan as to my knowledge there wasn't a formal plan in place. She couldn't tell me any details of the plan and eventually agreed there wasn't one. She then said she would freeze any further fees if I agreed to pay £10 a month. I offered to pay £15 and we set this up everything seemed fine. I have made the last 2 months payments meaning I should now owe £130. However today I have recieved a letter saying I owe £230 and at the end of this month another £100 will be added. I have phoned them again and they are looking into it but I just don't expect any help from them as they have been useless so far. I just wondered if anyone could give me any advice on where I stand, I am considering writing them a leter and sending it recorded as I don't actually seem to ever get anywhere on the phone with them.
Apologies again for the long post