First Hub6 faulty and so replaced by BT with what I now know to be a refurbished type A hub. Within hours of installing began to smell burning downstairs. After a while smell got so bad we had to open all the downstairs windows whilst we investigated the source. Quickly found it was the replacement hub 6 which smelled like burning plastic or wires. Informed BT who sent another replacement which I now know to be a refurbished type A for the second time. Day or so after installing got a burning smell similair to before. Once again found it to be coming from the Hub 6. Not only that but speeds on my infinity were eratic so called out the engineer. He spent 2-1/2 hours only to advise he believed it to be the Hub 6. I told him about the burning smells for the second time and he told me he would be recommending in his report that I get a brand new Hub 6 and not a refurbished one. Spoke with BT yesterday who advised me I would be receiving a "Brand New" hub 6 with all wiring and filters etc. Received replacement today and surprise they sent another refurbished type A with no filters or wiring. I called BT exec complaints were instead of sorting this out starting asking me questions about how and where I am plugging it in like some qualified BT engineer! BT guess what, I already had an engineer here for 2-1/2 hrs. BT need to totally overhall it's customer service approach as it's second rate. Told by Exec complaints they always send a refurb unit in place of a faulty one. I advised him engineer's notes specifically request a brand new unit. Told me he would try and source a type B brand new Hub 6 for me. These Hub's are designed to be left on 24/7 but based on my experiences I would not leave the house or go to bed with one of these still running.
If the ELC team are looking after your complaint then it should get resolved. It seems you have been unlucky with the Hub 6, for many including myself they work fine, to be honest most routers supplied by an ISP are not what you would call top of the range if you are not happy with the HH6 you can purchase an alternative make yourself and put the BT settings in.
BT of course would not knowing allow faulty routers to be sent out, if you for some reason you do not get a new HH6 pop back and ask the moderators to look at it for you. Although if you have gone to ELC thats about as high as it goes.