Allowed me to deposit and play over 2 days then blocked account because of self-exclusion from sister site.

I opened an account with this casino on 12/08/15 and deposited and played through £500 over the next couple of days. I tried to log on on 14/08/15 only to find my account blocked and when I queried it with support I was told I was self excluded from a sister site until January 2016. I checked and found that this was for Jetbull - I'd been having problems with the amounts I was spending so self excluded for a year. I then left a message with PlayHippo on 19/08/15 asking how I was able to open an account and deposit and play through £500 before my account was blocked and stating that it seems very unfair that I have played with money that I was never going to win anything with or have the chance to recoup and I would like an explanation of how this has been allowed to happen under the responsible gaming policy as in the past I have found with other casinos who operate sister sites if I sign up, I am then unable to deposit because my card won't be accepted.
Nobody came back to me so I forwarded on 20/08/15. I then got a response from customer service merely stating again that my account was excluded until January 2016. I responded saying "I did NOT exclude from Playhippo. I opened the account, deposited and played over a couple of days then when I went to log in to play more I was told to contact customer support.

When I did this I was informed that because I was self excluded from one of the sister sites I had now been excluded from playhippo. As I explained I am now aware that I am self excluded from 3 sister sites due to problem gambling and should therefore never have been able to open an account in the first place, let alone be allowed to deposit funds. Effectively, I have been allowed to spend £500 that you would never have payed out on.

I would appreciate if you could escalate this for a manager to have a look at and I am also going to send an email to the regulating body because in terms of responsible gaming, this seems grossly unfair.
I then got a response back from another agent apologizing for his colleague and saying my complaint had been forwarded to his manager and he would be in touch. I waited four working days (as stated on their website) and heard nothing so followed up with an email on 25/08/15 asking if they were any further forward with an answer to my query. Still no response. Emailed again 27/08/15 - guess what? Still no response. It's like they are ignoring me and all I'm looking for is an answer to my query.
Hope you can help!
Kind regards,
Julie