NO SERVICE AT ALL!!!!!!

I had a 100/100mb line for quite some time with Vox… On 21st October 2023 I requested an upgrade (NOT A CANCELLATION – RE-ACTIVATION OF SERVICES – AN UPGRADE) to 300/300mb. Never any assistance and after 18 working days you cut the 100/100mb line, leaving me without any connection on the 14th & 15th November. Vox did a new deal for the 300mb line - now charging me for both - the 100mb line + Pro-Rata for the 300mb line + a full month for the new 300mb line. Since end October 23 Vox have been promising to Credit my account for the incorrect double Charge. I've been phoning and emailing them since - with no joy. Every month Vox still take the debit from my bank. I've been a very loyal customer! Can not contact them as they transfer your call to non-active extensions every single time. No one comes back to me! Think I should just cancel my services with them and reverse my debit order