STOP PHONING ME!!!!

For the passed week I have been receiving calls of up to 10 times a day from both FNB's 011 *** numbers. The only reason I know it is them is because I had to Google the numbers. They phone in and as soon as I answer they immediately cut the call. This is text book Harrasment and should this be how they treat their valuable clients then I will have no choice but to close my accounts and move over to a more accommodating bank who does not harrass their customers. STOP IMMEDIATELY!