Grosvenor Casino - Issues with security team

I set up an online account at Grosvenor as I am a regular visitor to their casino and was made aware of the £20 free sign up bonus. Well after depositing £10 myself I won £500 so decided to withdraw. It wouldn't let me and they told me I had to verify my account. So i sent my passport and a HMRC letter for verification. These documents could be used to get police checks and have been used to verify myself in other government establishments but grosvenor said they werent. Their email stated i needed to send a household bill or a rent statement to verify myself but the house i live in is all in my partners name. Believing others would have the same problem there must be another way to verify myself. So i asked if there was anything else I could send? they replied with a list that stated I needed photo ID and a official document "such as" a utility bill etc etc. Such as implies this is flexible and since i had already sent documents which are seen as official in the governments eyes so they should be official here. But still no they refuse to help me they take ages to respond to my emails they've blocked my account too so I cannot log on. I tell them I have numerous documents which prove my address sent by the government. anyway I posted on here last night and had a response from their affiliate to send over my details still to here a response but would like to open this complaint now to start the ball rolling. I hope this can be resolved shortly. They also only seem to read one email response a day so iv sent supporting documents in but on a different email to my initial one from that 24 hours making the process a long and stressful one