Hello. i m having an issue with Tipbet about withdrawing my money from them

Firstly, I would like to say that the company is unacceptable in any sector and at their customer service, I would just say that on the subject of the withdrawal first time they asked me on multiple times not only for a proof of deposit (card) but also for movements of 2! of my bank accounts (but only one would eventually receive the money).

i will leave this issue for now and i will come to the main problem,when they finally decided to sent me the money they have sent me about 350 euros minus the amount of withdrawl.Upon asking them why they told me generally that these can be of taxes of winning from the greek goverment and might ! be from a second withdrawl the same week(which was the first and only withdrawl i made from them)

Yet i have contacted them again to point to them that they have calculated wrong ,my winnings dont even come close to be charged taxes by the greek gaming authorities( i knew that because from any other company i play i have never been subject to any tax based on my bets).Upon contacting another betting forum they have told me that indeed tipbet is calculating wrong(by will)
these numbers

I have any evidence for showing if needed,can any manager of tipbet help me with my case? otherwise can i adress the ibas or mga?
An help on this matter is appreciated,thank you
Kostas