Changing Flight

Think I know the answer to this but thought I'd get an expert view.
I was booked on VS046 tomorrow (17/3) but need to change to the following day. I think I am on an S class but it could be K - I have no ticket just the TA itinerary. Supposedly changes are allowed for 55GBP.
Anyway without asking for confirmation the TA booked me on the 46 for Saturday night (according to Manage Your Flight on the VS website I I am currently booked on both Friday and Saturday).
The TA admits he jumped the gun but has told me that there is no availability on the earlier flight (VS004) "at the discounted price". I have since checked on ExpertFlyer (which has all flights/cost classes wide open - 7777777) and also double checked with VS and it would appear that the TA is at best misinformed and at worst simply lying.
My questions are:
1. Is there a possibility that the TA is right in some way?
2. can a flight be changed with VS for the same charges regardless of who issued the ticket?
3. As the TA has jumped the gun and already changed the flight would a second change count as an additional 55GBP - I guess the TA is liable for it but just want to know where my company stands - more of a principal thing that a real hardship issue.
Thanks in advance for any help.
Phil
I was booked on VS046 tomorrow (17/3) but need to change to the following day. I think I am on an S class but it could be K - I have no ticket just the TA itinerary. Supposedly changes are allowed for 55GBP.
Anyway without asking for confirmation the TA booked me on the 46 for Saturday night (according to Manage Your Flight on the VS website I I am currently booked on both Friday and Saturday).
The TA admits he jumped the gun but has told me that there is no availability on the earlier flight (VS004) "at the discounted price". I have since checked on ExpertFlyer (which has all flights/cost classes wide open - 7777777) and also double checked with VS and it would appear that the TA is at best misinformed and at worst simply lying.
My questions are:
1. Is there a possibility that the TA is right in some way?
2. can a flight be changed with VS for the same charges regardless of who issued the ticket?
3. As the TA has jumped the gun and already changed the flight would a second change count as an additional 55GBP - I guess the TA is liable for it but just want to know where my company stands - more of a principal thing that a real hardship issue.
Thanks in advance for any help.
Phil