Thought she was going to London but she ended up in Sydney

I’m after some help in catching up with credit card bills

So my partner said she was going to London to catch up with friends for a few days. Gave her the space but then come the Friday to return no sign of her. Then she texts from Sydney. Icing on the cake was I paid for the business class flight as she used a joint account card but my name was the lead on it. Just going around in circles each month paying off the interest and not getting anywhere in reducing the balance. Any help to chip away at it would be gratefully received. 

https://paypal.me/fly1881