Hi Joe
Sorry it has taken me so long to get back to you - as Bobby said I was on leave. I would recommend coming back through to the guys on Livechat here, they can take a look at this for you again and can arrange an engineer. I know that they advised you of charges - but these charges would only stand if it was your own equipment causing the issue. If all the engineer has to do is uncap the line then to my knowledge there should be no charge. We are unable to book engineers without the customer accepting potential charges, but as I say for a simple uncap and SNR reset - as long as there is nothing on-site causing that issue - it would be unlikely to be chargeable.
I hope you can get this one resolved ASAP!
Regards
Ryan