This may not stop the calls but just some information that i got of of a rather helpful agent at HSBC's Southend customer credit services 0845 600 6423...if its true or not i cannot garantee but i had the same problem so i had a few questions written down before i called and these are the responses i was given. HSBC call out on each number they hold 3 times a day. Sometimes when an account is opened in the branch telephone numbers are imput in the home, work and mobile field which can lead to up to 9 calls going out on the same number. If you delete your numbers it can take up to 48 hours for the number to be removed from their system and if you are in collections for a long time, they have a trace team that find contact numbers for customers that they need to speak to. from their outbound centers they need to confirm 3 peices of information they have to state your full name you need to confirm the month and the year of your DOB and then they will confirm back to you your post code, if after this point they can, if you request... confirm any question you have relating to your account so that you know that you are speaking to HSBC. They have to pick a "dissposition code" after every call so if you hang up they will choose"disconnected" which can lead to further calls being made untill the call is completed. I told her that i didnt like speaking with their collections agents but it would seem that i would have no choice other wise the calls will keep comming out to me, she reassured me if i didnt go through the call or have a missed call to contact the customer credit services number, aslong as they can discuss the reason for the collections calls then they can stop the calls for the rest of the day, but unless a solution is made they cant stop them...but personally i found them so helpfull i dont mind calling in if it means for the rest of the day i can relax. The only down side is, is that they have 2 dept and if they are all on the phones in southend apperently the calls go out to one of their global teams.