ANNOYING CALLS

My mother has already spoken to 2 of their agents, one of which was very rude. She told both of them that she was not interested in their product. Instead of them getting the message and stopping with the calls, the opposite is happening. She gets so many missed calls everyday from them. Missed calls because I have advised her to ignore I have true caller, so I check tbe numbers. She blocks one number, a couple of hours later she gets a call from another number. The numbers range from codes 012, 087, 014, 010. Enough now, PLEASE STOP CALLING MY MOTHER.