HSBC Credit Card Excessive late payment & interest fees( Lost mail) slow to post payments Grand City Of Industry California

Grandson went over his limit on two credit cards from HSBC---Interest rates are obcene and rates horendous! I paid them off in full by mailing two checks well before the due date. Claim they never got them after 9 days and they have not cleared at my bank. Now they have added another over the limit fee and interest and only will respond that the " mail must be lost". I cannot file a 1510 U.S. Postal form until 14 days it says to allow. Worst credit card company in existance. Requested that both account credit cards be cancelled after I paid the FULL balances. Of course, they will not until the grandson calls them and the accounts paid in full ( which I thought I had done on May 5th with the due date of the payment May 15 on one and May 18 on the second one. What a run-a-round- BEWARE!!!

Walter
Tacoma, Washington
U.S.A.