M&S Energy Fix and Save

Grippy_Scot

As a member of the MSE Energy Club I selected the M&S Energy Fix and Save Tariff. On the website it showed £30 cash back through the comparison site and £20 M&S voucher. Out of the blue on Saturday I received a letter from M&S Energy advised me that the postcard that they recently sent me (which I did not receive) advising I would receive £20 voucher was wrong and contra to their terms and conditions and that as a courtesy they were now giving me £5. If you go direct to their website it says:

M&S Energy Fixed Price Dec 14
Be a bright spark.
Switch, fix, relax.
Join today and enjoy peace of mind with M&S Energy Fixed Price Dec 14.
Choose this option to:
Fix your energy prices
Get peace of mind on your energy prices until 31 December 2014. Let M&S take care of your energy needs and fix your prices.
Get up to £20 of M&S vouchers*
When you join for both gas and electricity, you'll get £20 of M&S vouchers to treat yourself in store. For electricity you will receive a £10 M&S voucher.
Spread your payments out and save
Most of our customers choose to spread the cost of energy by setting up a monthly Direct Debit. And you'll receive a discount of up to £80 off your standing charge per year when you pay this way≠.
Manage your account online and save a further £12 per year
With paperless billing, get the convenience of having access to your energy account 24/7 and save up to £12 off your standing charge per year too≠.

A £50 exit fee applies if you leave the tariff more than 49 days before 31 December 2014.

but if you look at the T&C's it does state that the cash back is not applicable if you go to them through a comparison website. If this is the case then why was the M&S voucher shown on the comparison for the Energy Club if it was not applicable.