extortionate over charging

I booked a return journey FOR 2 from Stoke on Trent to Paignton costing £190,when trying to book it wouldn't give me reserved seats for the return journey, i phoned red spotted hanky and was told there computers had been playing up but book it then call back and they would sort it.
My confirmation email stated no reserved return seats phoning again I was told it was because I hadn't specified a time for the return journey, when I pointed out that I had they said yes you have you will receive another email with your seat numbers, 2 days later I got another email saying they couldn't do anything after another phone call they said it might be because the train was full or I hadn't specified a time for the return journey, when I told them I wasn't standing up for over four hours and pointed out I had specified a time they said I would receive another email with seat numbers, 2 days later I did get another email this time I did get reserved seat numbers at the 3rd attempt.
After all this I went to my local train station to print my tickets, and yes no return seating, after asking a very helpful attendant at the stations booking office he printed my tickets off and yes they had reserved seat numbers.
Just when I thought it was sorted the attendant asked why have you paid £190 when you should have only paid £89.60, in despair I phoned yet again when I got home and was told it was because I hadn't specified a time and had paid for a anytime return ticket when it clearly shows the time on all my emails, Rubbish Service & Rip Off Merchants