Well, I do not agree with Mr. Hitesh Arora.
And Simi, how can you conduct business based on an EMAIL ACCEPTANCE or without having any proper Agreement/Acceptance of Proposal in physical form with them? This is not the right procedure and work style to run any business. You need to adopt a proper system if you still do not have one.
Now, I want to let you know that you cannot treat their EMAIL acceptance as an AGREEMENT with you. Though this can be counted as only CONSENT, not an agreement, which has a unique power and dignity and a different meaning in a legal perspective. I understand your concern, but if you never had any paperwork with them, you cannot take legal action against them.
Second, I would suggest you visit them and try to negotiate and convince them with a humble gesture, and this can only work for you.
@Mr. Harish, can you please let me know about any case where one has taken legal action against anyone on the basis of an EMAIL Acceptance? I would be really grateful to you. Because there are a number of people accepting email offers and refusing, and if people started taking action just based on Email acceptance, then we all can imagine how much pressure is going to increase on the LEGAL SYSTEM and how much TIME is going to be wasted...