My phone got stolen I been trying to ring customer...

My phone got stolen I been trying to ring customer service number and there are 100s deferent numbers on Google for lebara and none of them work some of them ring and it gets disconnected no one answers..
Obviously only the reason behind that I can think of is because every time I ring from my mobile they charge 50p per call to customer service.. and now I'm not using there 5588 number instead I'm using a landlines number and I belive they can not charge me 50p for that call so they rather let it ring and not answer
So annoying once I get through I will get the sim blocked and move on to lyca or something