Mistake in Schengen Visa form - forgot to add applicant

[iamvivekmahajan]

Hi All - I have made a mistake and need help. I am applying for France from UK - short term tourist visa using TLS. I had filled in my Visa form on the French embassy website. However, I made two mistakes:
1. Missed out to add applicant of my son
2. Updated incorrect French Visa form number (as I had two French visa forms).

I blocked the appointment but didnot pay the appointment fees yet.

System tells me that I will lose the appointment in 3 days if I don’t pay booking fees. I was fine to lose the appointment and apply for a fresh appointment however my existing blocked appointment is not getting released. I am not even able to apply from a fresh TLS login as it identifies my passport number.

What should I do? I tried endlessly to call to TLS but never gets through/never receive call back. No response to my mails.

Should I pay the £30 fees and then amend the application? Will it allow me to add my son, applicant if I pay £30?

Any guidance will be highly appreciated.

Regards,
Vivek