The clubs says the deadline will not be extended and say on the official website
"Don't miss out on your Season Ticket, the deadline is on Saturday. You can get them now by calling 0845 345 1400 or you can order online. Click here!!
Call the Ticket Office and ask how you can split the payment up into 4 equal parts. Don't forget you can get an entire season of live football for just £199 and there are free under 9 kids tickets available in the family stand. Kids over 9 are only £69. Adult seated tickets start from just £299 and adult terrace tickets start from £199.
So you could for instance get a full season ticket for just four £50 payments."