Handy simlocked after using pay-as-you-go?

[AC Question]

Heyho,

I recently been to England and bought a british pay as you go card for my german phone.
When using my german sim-card again, it says that the network is blocked. I can neither use the telephone nor use the mobile internet.

Is it possible, that the pay as you go simcard locked my phone?

Thanks for the Answers

MoriMori