Extremely poor customer service

After years of loyalty to this company they have failed dismally to rectify a problem posed by both their poor customer service and their couriers, I had an online contract upgrade in November and had been phoning and emailing for assistance but was only told my deal was cancelled (nobody notified me ) till I made follow up enquiry. It’s like this company is so useless when it comes to takin hha care of their customers , they just say sorry and that’s it. This is unacceptable from a big company like this . I have voiced out my frustration, inconvenience and dissapointment but have found no joy . I hope someone somewhere out there is willing to assist me.