Billing, no services after part paymnt

Overcharged billing, tried to call they droppiing calls, asked to be called back nothing that was from Sunday, I did a part payment, services activated for few hours, off no wifi, they don't pick up calls, no return of that call back they have on their system, the whatsapp line is just for Vibes no one ever responds...I work from home and all this is making me annoyed...what must happen to get my wifi connected? For me to work, why have a policy of part payment but doesn't work, why have callback but is not effective...no communication line whatsoever, only great communication when it is sales after one is doomed.