Paying bills that just dont match up and unable to tally them!!!!

<p>My mother was admited at the end of last year to the New Somerset Hospital and treated. Subsequent to her treatment, I have recieved a couple of invoices through the post. For those invoices that have been recived, I have paid - and I have the POP to verify this. Subsequently I have recived final demand letters informing me to pay outstanding values - for which I have no record of an invoice or anything. Having called the hospital and spoken with the staff there, I was then informed that after an invoice has been paid (as I can now see on the statement), there is in fact an adjustment made...where more money owed is added to the account!!! This seems to me to be very strange - almost as if I am being penalised for paying the bill. Additionally, I have never recived invoices for these 'adjusted' amounts!!!! To make matters worse, these amounts have been handed over for collection (which I have recived notice for via sms).....how was I supposed to know these amounts were even due in the first place? I still have no invoices for these amounts. I elected to pay one of the amounts and it has taken 2 weeks for them to send a statement reflecting that this has been paid, but the statement that the hospital has sent me, does not reflect a number of my payments. I have tried to phone, I have emailed...but no response or explanation can be given as to why I firstly get more money added to an already paid bill, and secondly, why they have not reflected the true amounts outstanding!!!!!!!! I have offered to pay the amount that I belive is outstanding...but this is not the same as their systems values...so it would seem we are at a stale mate and I am the one that is getting the raw end of the deal!!!!!!</p>