Hi! the deal you purchased was through Groupon and offered you 24 units for $229 That was a fantastic deal at only $9.54 per unit. As stated in the terms and conditions any extra units needed to achieve your desired results would be at an extra cost. Choosing to not get the extra units you required would result in unwanted movement. Our units are priced at $12, nowhere near the $30 you calculate you have paid especially as you were using a voucher. We only use the best products and experienced practitioners who always advise on the correct unit amount to achieve the results you desire. If you wish to discuss this further please do not hesitate to make a booking. Kind Regards.