Ref. No. 40/1161
In the name of Allah the most Gracious the most Merciful
The answer to your question is as follows:
The banking system is totally based on interest. According to Islam, interest based dealing is haram and unlawful. So opening CSP and availing this service is indeed helping in interest based banking system, hence it is not lawful for any Muslim to avail such services.
Darul Uloom Waqf Deoband