Service not delivered

Simply pathetic service! The last day of my previous contract was 29/07/2022. The following day was supposed to start the new contract and I never got the service. I called the advisors and they told me to take out the sim card and put it back in the phone, also to check the sim card in another phone. None of these methods worked. I started writing emails to customercare and initially I was promised that the technical department was going to look into the situation. Their feedback is to give me a call, which for obvious reasons is never going to work! I asked them to write an email on the latest or to give me a call on my UK number. None of that happened, currently they just simply ignore my emails. I had a similar problem in the past and the only way to resolve this was to continuously be in their offices. I'm in the UK and can't do that. A month later, I'm paying for a service that's not provided by them.