1. Well, it is not clear whether there was any Non Compete Agreement was executed between you and your previous employer to restrain you to have trade in the same field for certain period of time.
2. if there is none then there is no legal bar to carry out similar trade.
3. Even if there was such agreement then also such stipulation is not enforceable in all circumstances.
4. So you can very well ignore such demands and carry on your usual business as before.
5. You have the option of filing a Caveat in local court to avoid ad interim injunction against your present business.