Rain refuses to cancel my service

I cancelled my service last year in December, I was informed by an agent that my router will be picked up... I never received any call from them till today...tried reaching out to the customer service line up until my airtime finishes due to long hold...no one even bothers to reach out to me after attempting to call several times to call and request for a call back...currently I'm almost 5k in debt due to them refusing to cancel my service in time when i requested for it....I had so much faith and trust in Rain but my views have changed