remove() function doesn't work as expected - c

Question

I am working with a code that generates a fixed number of files and keeps that number. After every new file is created, an old one has to be deleted. This is the code:
#include <stdio.h>
#include <stdlib.h> // needed for malloc
#include <string.h> // needed for strcpy
#include <unistd.h>
#define Extension ".txt"
#define LOG_MIN_FILENAME_SIZE 32
#define NBR_OF_FILES 6
char buffer[LOG_MIN_FILENAME_SIZE];
int timez = 0;
int minutes = 0;
int count = 0;
FILE* pf = NULL;
char* ListOfFiles[6];
int main(void)
{
for (int i = 0; i < 3; i++) {
ListOfFiles[i] = calloc(LOG_MIN_FILENAME_SIZE + 1, 1);
}
for (int i = 0; i < 10; i++) {
sprintf(buffer, "%d" "%d" Extension, minutes, timez);
if (access(buffer, F_OK) == -1) {
pf = fopen(buffer, "w"); // create the file
count++;
fclose(pf); //closing the files is necessary
if (count >= NBR_OF_FILES) {
remove(ListOfFiles[0]); //remove the oldes file.
}
for (int i = 0; i < NBR_OF_FILES - 1; i++) {
strcpy(ListOfFiles[i], ListOfFiles[i + 1]); // u cant use just normal assignment because it copies the head ot the pointer rather than the actual content of it
}
strcpy(ListOfFiles[NBR_OF_FILES - 1], buffer);
}
timez++;
minutes++;
}
for (int i = 0; i < NBR_OF_FILES - 1; i++) {
printf("%s", ListOfFiles[i]);
}
}
In the output, I get only one file created at a time (with every execution). When I execute the program more than NBR_OF_FILE times, no files are deleted! Do you have any idea that what the issue could be?