UNSATISFACTORY RETURNS/REFUND POLICY

I ordered a security safe online and it was delivered to me 4working days after order. I paid COD for the good on delivery. I suspected something wrong with the goods since the weight was too light. I informed the delivery guy without being hasty that I would weigh the good at home and inform him asap when I want it exchanged or refunded. I weighed it at home thereafter and immediately informed takealot about the return and they logged it online. The agent informed me that they will collect the goods and that I will have to wait 21days for my exchange or return. I indicated that this is unacceptable and that I would want the correct good to be sourced by takealot and then an exchange should take place when they collect from me. I was informed that they cannot operate like that since it is against their returns/exchange policy. I then informed the agent to reimburse me immediately on collection, so that whilst I wait for them to source the correct good during the 21days I have the option of seeking a correct security safe somewhere else. This was logged accordingly by the agent and an email sent to me confirming collection date. On date of collection (4days later), I contacted the courier company and enquired regarding the instructions they received from takealot, and they said they were only informed to collect, not reimburse. I contacted takealot, and requested to speak to the agent that logged the return upon which I was refused. I then requested to speak to the manager, and I was likewise refused, hence the reason for this complaint. I am of the opinion that irrespective of the returns/exchange policy, it is only ethically correct that if certain conditions are agreed upon like the refund on collection that it should be honoured. Also it does not make sense how can a purchase take 4 working days, whilst a refund/exchange takes place 21 days.