From the example given for PRUcash double reward in the website, if one were to contribute RM20180 annually for 10 years, by the end of the 20th year, they'll get RM222181.

However, do note that this amount is viable only if Prudential's gross investment return p.a is 7%. You'll have to ask the agents what is gross investment return for this item in the past years to know if this is a good indicator.

Including the annual guaranteed payout and the final payout, it should add up to RM324181.
If you were to place RM20180 annually in FD for 10 years and let the interest compound for another 10 years, by the end of the 20th year, you would get RM307948 (assuming FD interest of 3.15%), which is just RM16232 lower than what Prudential gives.

And if you read the fine print, the RM222181 final payout is inclusive of bonus payouts which are not guaranteed.

So, the question is can Prudential have an average annual return of 7% for 20 years?
If you invest on your own and would manage to get an average return of 4% annually, you would have get more returns than that given by Prudential in their illustrated example.

As a savings plan, I would say you would be better off if you invest by yourself.