So many problems, no one to help!!

I have been with 3,for many years now, convinced my whole family to convert to 3. However the last few months have been shocking, the customer service has been disgusting unless speaking to a manager, who helped resolve the situation and without him ( Prusean- Customer service manager) 3 would of lost me as a customer.
Firstly my ex partner ( that I have not spoken to for 2 years) somehow got an upgrade using my account details, which 3 authorised. With this I tried to cancel it and the contract which apparently I could'n t do!! After 12+ phone calls, shouting, tears and being emotionally drained I got through to a manager who finally could help. The service I received before him, was awful, I have never known anything like it!
I then received a slight discount as compensation, which then the wrong handset got delivered, with this I called and got advised could change the delivery address- 4 calls later and being put through to yet another manager, I got it changed! I think 3 need to look at what their teams are suggesting and advising to their customers, as I only followed instructions given by 3!! I think it's hilarious how they can authorise an upgrade without my permission but when it comes to my convenience of when a handset can be delivered, then there always seems to be an issue or security reasons- UNREAL!
Extremely disappointed and major trust issues at the moment with my current network of 5 years!!