Terrible service

I wanted to start a new contract. Everything was approved then came the mandate. I tried to accept it on my side which it failed due to technical error after phoning back and forth i phoned my bank who then told me the mandate was approved. Just to get a sms to say my order has been cancelled with no explanation and this after i phoned again and said that has been approved on my side and still no call from any consultant. This is beyond frustrating as the item you want you cant get and you have to settle for something else just to sit with this. And then when i want to phone the sales department i get told rhat due to me phoning regularly my number has been blocked but i phoned sales ONCE!!!