Link to the rules is here, and there is related to 'refund' which I found in the text of the rules:
"Paid subscription canceled by Subscriber is not refunded."
"You can suspend trading under the current Subscription whereby the Subscription will not be canceled and the fees applicable during the "freeze" period shall not be refunded. The "freeze" period cannot be carried over to the next Subscription period, i.e. it will not be taken into consideration when subscribing for a new period."
Forum on trading, automated trading systems and testing trading strategies
Eleni Anna Branou, 2018.08.24 13:12
You can get a full refund if you unsubscribe within 24 hours of your subscription.
Otherwise, you have to contact the Service Desk.