default notice

If a default notice served under section 87(1) of the consumer credit act 1974 shows the the wrong amount for the total amount payable under agreement is it defective

But the error could impact down the line if the default was not satisified as in the termination of contract and the balance owing was wrong,
I cant find any regs or cases on this, if it was just time frame and set out of doc it would be easy to validate
I find it hard to believe that a major company can get a legal document wrong and say oh well its just admin error we didnt mean that,why bother with any docs if they get it wrong they can just plead stupidty

It`s in the lenders favour to the tune of £1500, If I query it with the company it will give them time to rectify,as they have already terminated the contract and are threatening court for the full amount ,
They issued a default notice after one missed payment, that was feb 13th and terminated 3rd march,