Fibre Costs on slow line £14.99 or £19.99 ?

[#1]

I am paying £19.99 a month (plus line rental saver) for "Plusnet Unlimited Fibre". I'm a long way from the cab and only get less than 20Mbs sync. Is it possible for me to switch to some different account where I only pay £14.99 a month?
When I try to change products it only shows me my current product.

[#2]

you need to phone customer options and they should also offer you a deal with a tie in
    From landlines: 0800 013 2632
    From mobiles: 0330 123 9197
    8am - 8pm Monday to Friday
    9am - 7pm Saturday
    9am - 6pm Sunday

[#3]

Your pricing depends on the product (if you are on a 'legacy') or market area. As is suggested above, I'm sure we can sort you out.

[#4]

It was well worth calling in, thanks.