Complaint Review: Best Buy - HSBC Retail Services

I have spent literally hours trying to clear up Best Buy payment issues.  After promising to change payment schedule from 1st to 10th of cycle, with confirmation, I was told this was not possible the following month after calling back again--thus receiving late charges AGAIN.  After paying ONLINE, ONTIME, was then told that payments could not be posted for 2 days, thus being late again, even though payment was made on time.  Again, after a phone call, was reminded that payments, even online direct, could not be posted after something stupid like 4 pm and take 2 days to process.  Customer Service agent said she would lift late charge when she saw my posted payment.  Surprise, surprise, I open this month's bills--no credit--just another late charge.  Seriously irritating/frustrating as I have always been conscientious and am extremely angry with their policies.