I'm sorry that the ring tone increase hasn't been increased for you after you requested it as we can increase the ring tone but it depends on your area due to the particular switch you're hosted on. Other customers in a different part of the UK will be different.
Using the details we have, I've had a look at your switch area and can see that it can be increased from 6 and 10. Due to the restrictions, the number of rings can only be either 6 or 10 so if you're already on 10 rings, we wouldn't be able to increase this.
Please let me know if you're on 6 rings and want to extend it to 10 rings so I can it done for you.