Cancelling Three contract within 14 days

fossil

We took out a unlimited 4G broadband contract, which includes a Huawei 4G router, last week. However, the speeds are not consistently good. 
Should we go down the route of complaining about the speed and showing evidence, or as we are within our 14 days should we just return it and end the contract, with no reason required?
When we bought it, we asked about return if it wasn't up to speed and the salesman said he was absolutely confident that we would have good speeds in our area (which he had checked) and wouldn't need to take it back. However, when pushed, he said if we really found it didn't work, we should take it back to him personally at the store. Should we do that, or is it safer to go through the general customer service/returns service? In a way it might be easier dealing directly with the store, but also, I should imagine that if we take it back to him personally, he may well convince us that even though there was a problem, it will be fine next week. 
Any advice or reassurance appreciated. This is all quite daunting.

eDicky

It might be easier to advise if you name the shop and service provider. It's doubtful whether you have 14 days' 'cooling off' period for cancellation if you didn't sign up online or by phone, and the chances of encountering the same salesman in a shop are uncertain. Have you already reported the service shortcomings..?

sdduk

I agree with eDicky and afaik you don't get any cooling off period if brought from a shop so you could be stuck with it, also if they do release you from the contract get yourself some Payg sims and test before committing to another contract or ask friends and family what provider is good in your area even ask a neighbour it could save you a lot of problems again in the future.

fossil

Thank you for these replies. I will go into the shop this week, but understand I may not be able to leave contract then.

Pluto88888

This is why I always order online or over the phone ordering online you get the 14 days cooling off period/cashback you can always use three live chat and explain to them you feel very unhappy with the speeds and the service and wish to make a formal complain they might let you leave for free.

link to the live chat http://www.three.co.uk/support/Contact-Us normal chat 
if you get nowhere in normal chat use this complaint chat route http://www.three.co.uk/support/how-to-complain