My phone won't charge?

Hi all,

I've got a problem. My iPhone 5s had trouble charging for a while but I was able to charge my phone if I play a bit with the cable. (tried diff cables aswell)

I went to a Apple Store and they said "It's probably dust inside the charging port". She cleaned it out for me using the item you use to open the simcard holder.

I went home, and when I got home I wasn't able to charge my phone at all!! Therefore I called the Apple Support and they told me it's out of warranty. Repair costs will be up to 260 euro. But I do have the feeling it caused by the worker in the shop.

What can I do?