Each person engaging or continuing within the county in a business subject to the sales tax authorized to be levied in Section 45-11-244.02 shall add to the sales price and collect from the purchaser the amount due by the taxpayer on account of the tax. It shall be unlawful for any person subject to the sales tax authorized to be levied in Section 45-11-244.02 to fail or refuse to add to the sales price and to collect from the purchaser the amount herein required to be so added to the sales price and collected from the purchaser, and it shall likewise be unlawful for any person subject to the tax to refund or offer to refund all or any part of the amount so collected or to absorb or advertise directly or indirectly the absorption or refund of the tax or any portion thereof.