HSBC Credit Card — HSBC Mental torcher

I have been using my HSBC Gold card for more than 4 years now without any problems. there is a Skypak drop-box close to my office and this where I have been dropping my cheques. I dropped my payment cheque on 15-Nov-2008 which was well before the due date but for some reason the cheque (it seems) never reached HSBC. "After" the due date they call me up and state that the payment is not received. I agree to issue a stop-payment on my first cheque and drop a second. This was on 30-Nov-2008 .Common sense would tell anyone that it takes atleast 2-3 days for it to be cleared. Since 31=0th until yesterday night, I have been receiving not less than 50-60 "missed calls" every day at all times from HSBC, Chennai. The calls are never completed. "I" call back asking what this was about and I repeat the whole story. The same process repeats with me calling HSBC back every day and stating the same things all over again. Receiving unsolicited calls is one thing; getting 50-60 "missed" calls from a comapny of the clout of HSBC was rather surprising and shocking. And the best was this... each and every time I called up, they already have all the information I had already told them...
I hope HSBC takes cognizance of this.