I heard this yesterday during a news interview on a local television station.

Problem:
The adverb “back” makes the statement self-negating.

Explanation:
To “credit” an amount to someone is to refund what that person had paid.

The “re” in “refund” means back. Therefore, one could argue that a “refund back” action would never reach the intended recipient.

In other words, the adverb “back” should NOT be used to modify the verb “credit”.

For fun, I searched Google for “credit back” (with the quotation marks). Unfortunately, I could not use the results to get a reliable estimate of the number of erroneous instances because there are many instances on the Web of correct use.

For example, “Colorado lawmakers want to bring tax credit back.” is an example of correct use of “back” after “credit” because “back” in this sentence is modifying the verb “bring” instead of the noun “credit”.

Solutions:
“They credited me the whole amount.”
OR
“They credited the whole amount to me.”

I saw this in a presentation to customer-support personnel.

Problem:
The word “back” is redundant in this expression.

Explanation:
The expression was part of advice to customer-support personnel:

“Come to work with a smile on your face! That smile then brightens everyone’s day[,] which reflects back to our customers. A smile goes a long way over the phone when providing Best in Class Service.”

The “re” in “reflect” means back. Therefore, one could argue that a “reflects back” action would never reach the intended recipient.

Solution:
“… which reflects to our customers.”
OR, even better, given the full sentence,
“… which is transmitted to our customers.”

I came across a word — “irrespective” — that seems to explain how “irregardless” got coined.

Problem:
As I wrote last October, “irregardless” is meaningless in that it means the opposite of what is intended.

Explanation:
People use “irregardless” when they mean the adverb “regardless”.

I now believe that another source of confusion is the fact that “regardless” and “irrespective” have the same meaning.

Blend these two words together, and you get “irregardless”.

Solution:
“Regardless” or “Irrespective”